NASCAR's Austin Dillon to drive Tony Stewart's car at Michigan race

Dillon, 23, currently leads the title standings in NASCAR's second-level Nationwide Series, and he was the 2011 champion in NASCAR's Camping World Truck Series. He's also the grandson of NASCAR team owner Richard Childress.

"I've watched Austin for many years and at each stage of his racing career he's been successful," Stewart, co-owner of his Stewart-Haas Racing team, said in a statement. "I know he'll perform well at Michigan."

Stewart, a three-time Cup champion, suffered a broken right leg a week ago while racing sprint cars in Iowa.

The 42-year-old Stewart required two surgeries to repair the leg and was released from the hospital Sunday. He's been sidelined from racing indefinitely.